A girder type track for guiding a vehicle, such as a track for supporting and guiding a monorail car is well known.
Japanese Patent Application Hei-2-63752, discloses a switch track for use in a switch portion of such girder type track comprising a movable girder arranged on a fixed supporting member and driven by an external drive means such as hydraulic cylinder to switch one main track between a plurality of other main tracks.
In such a girder type switch track, means for moving the movable girder occupies a large space.
In order to solve this problem, a mechanism has been considered which employs a mechanical drive device mounted on a fixed supporting member and switches the movable girder with a mechanical drive device (Jpn. Patent Application Hei-2-225499).
On the other hand, a girder type track for a magnetic levitating type linear motor car is usually installed on or above a road. Therefore, such girder type track should be concordant with space in a city. Otherwise, installation of such track on a road might be objected to.
In the above-mentioned mechanism for such a girder type track, there is a tendency for the fixed supporting member to be thick since the drive device for driving the movable girder is mounted on the fixed supporting member. In this mechanism, the sum of heights of the fixed supporting member (or base girder), the drive device and the movable girder, that is, the distance from the lower surface of the fixed supporting member to an upper surface of the movable girder, is large. If the height of legs supporting the fixed supporting member is included, the distance will be very large and, therefore, underground portions of the legs must be deeply buried in order to sufficiently withstand the load related to the whole height of the switch track. Such structure can not be considered to be optimum for a magnetic levitating linear motor car.